Known wedge plate clutches, for example for use with all-wheel drive applications, typically use one or more one-piece, scalloped, single-split wedge plates to connect and disconnect two shafts. A single-split wedge plate results in unequal locking pressure in a locked mode, non-rotatably connecting the two shafts. As a result of the unequal locking pressure, the torque-bearing capacity and durability of the clutch are compromised. Further, when the hub of the clutch is mounted to a rotating shaft and the wedge plate is mounted on the outer tapered surface of the hub, in the free-wheel mode (the shafts connected to the clutch are to rotate with respect to each other), centrifugal forces from the rotation of the hub at high speed can force the wedge plate to move radially outward to engage the inner ring of the clutch, resulting in an unintentional shift to the locked mode.
To address the problem of unequal radial movement of the wedge plate, it is known to replace the one-piece wedge plate in a wedge clutch with a plurality of circumferentially aligned wedge plate segments. The wedge segments are arranged around a tapered hub and are positioned with a retaining ring functioning as a spring. However, the retaining ring, like the one-piece wedge plates, has a single-split and therefore does not allow equal radial movement of the wedge segments. The single-split design also limits the ability of the retaining ring to prevent undesired radially outward displacement of the wedge plate segments (due to rotation of the hub) during the free-wheel mode.
Further, known wedge plate clutches have a wedge plate or wedge plate segments having ramp surfaces on the smaller inner diameter that engage with ramps on the outer surface of a hub or inner race. Thus, friction contact forces are concentrated on the smaller inner diameter of the wedge plate or wedge plate segments, limiting torque carrying capacity.